My company works with dye-sub photo printers. Assuming that it is a similar process, dye sublimation is an extremely expensive printing process. there are three basic components:
- Thermal print head
- Dye sub ink (three or more colors of ink on a plastic sheet.
- dye receptive media: Paper or in this case keys.
Thermal head heats up and produces the pattern of the image against the dye film, against the receptive media. It has to make multiple passes against the media (one for each color). Color doesn't really apply for the keys, but I don't know how many passes it takes for the letters to be the desired bright-white.
Reasons that it is expensive: the dye film is not reusable, and a lot of it is wasted (not transfered to the media) and the thermal heads have a short life span. In the photo industry, the heads cost several hundred dollars and are only good for about ~70,000 prints. The dye film is not cheap either, and often comes on proprietary rolls (each has a special RFID code).
I would be curious to know how the key thermal printers work, but I'm guessing based on my experiences, laser printed keys are probably cheaper.
